Answer
numerators, denominators, $\frac{2x}{x^{2}+4x+3}$
Work Step by Step
To multiply two rational expressions, we multiply their ___numerators___ together and multiply their ___denominators___ together. So $\displaystyle \frac{2}{x+1}*\frac{x}{x+3}$ is the same as $\displaystyle \frac{2*x}{(x+1)(x+3)}=\frac{2x}{x^{2}+4x+3}$